@rgp102
Hello and welcome!
I can give you my thoughts on both budget and experience living in Lisbon. I've been here almost three years, moved from the US, am semi-retired, and live in the Avenidas Novas area of Lisbon.
Note that many others will disagree with my thoughts and that's fine....the below are just one person's perspective.
Lisbon is an amazing and wonderful place to live. I would suggest if you want to live in Lisbon, and you lived a "middle-class" or above lifestyle in the United States, then you will likely need a decent sized budget to partially replicate that lifestyle here....albeit still much cheaper than the US, probably a lot more than most "Retire to Portugal" websites would lead you to believe.
More expensive than US
- Rent and/or buying - Rent in central Lisbon is high compared to most US cities. Since you have lived in the most expensive cities in the US, you may find rents here relatively cheap. Finding an apartment you really like may be a bit of a challenge. Coming from the US, most apartments (built in the last 30 years) have design features hard to find in Lisbon. For example, most places I've seen here tend to be very compartmentalized in their design. Meaning you have a separate room for a kitchen, a separate room for a living room, and a hallway with small bedrooms lined up next to each other. The more modern apartments may have an open kitchen/dining/living room concept but these apartments (while very modern) tend to be expensive. Also, don't judge an apartment by the exterior. I've seen many an ugly and run-down looking exterior or very sterile looking exterior building have very lovely renovated apartments. It's probably not hard to find a renovated apartment that looks nice, but if having an "open" plan is important, that will be tough. It may not matter to many people, but this was a big deal to me. I would think a budget for a T1 (i.e. 1 br) in central Lisbon would cost up to $2K+/month. Going outside of central Lisbon will obviously be cheaper.
- Utilities - while I think the amount spent is more a function of the relatively small apartment sizes, the cost per sqm. is high. For our T3 apartment, we spend on average of about 300 euro a month for gas/water/electric. We spend the most during the cold months as gas for heating tends to be expensive.
- Name brand clothing - I find that international brands (i.e Nike, Ralph Lauren, etc) are pretty expensive here and more than I would pay in the US. Since I've been here, I've opted to buy "local" Portuguese made clothing which is significanty cheaper. I can't talk to the quality of the local brands as I haven't owned them long enough but so far so good.
Cheaper than US
- health insurance - for us, the biggest savings. I know there is a lot of debate on the qualify of care and accessibility to it. All I can say is that when I've needed it (which fortunately, hasn't been a lot) it has been easy to get and effective. We spend about 275 euros per month for the most expensive private insurance plan and we have access to the social insurance. We have no deductible and our co-pays are minimal.
- groceries - budget would depend on how much convenience you want? Do you make everything from scratch or do you prefer heating dinner up in the microwave. I would recommend about 75 euro a week for a good blend of both. Fruits and vegies are really cheap.
- dining out - good qualify food and lots of options for a very reasonable costs. Dining out in the US has got to be stupid expensive. Even with the rising costs we've seen over three years, it's still a bargain and the food is great. For me, about 15 euro for a modest lunch dining out and 30-40 euro for a decent dinner.
- cell phone / cable / home internet - you should be able to get this all for under 100 euro a month (excluding cost of phone).
- wine - some of my favorite in the world and ridiculously cheap.
Other
- Education - I'm assuming you are retired and single so this doesn't matter. For others with children, the cost of an international school (if you opt not to educate with local schools) will cost between 15K-25K euros per year for a school that offers an IB or A-levels curriculum.
- automobile - buying cars here is very expensive. We own, but only drive about every other week. We have monthly passes (Metro and bus) and pay 40 euro a month.
In terms of overall monthly budget, for me, 4,500 euro would be at the low end if living by myself. I know you can live outside of central Lisbon for much cheaper and I'm sure others live in central Lisbon for far less and are quite happy and content.
One last thought....we live in a really nice (expensive) part of Lisbon. It costs us a lot more than we initially planned. Fortunately for us, moving to PT was not about cost but total lifestyle. While more expensive than anticipated, it really is an amazing place to live and i would pay more if needed.