You're welcome. This price was from 2012, but I doubt it has changed significantly since then. The rate with the UK is not good right now, it had a massive crash after the vote to leave the EU and hasn't recovered. It has been floundering around $160 something for a good while now...
There are a few stonemasons listed under 'Monuments' on the Jamaican Yellow Pages website, where you may be able to get a quotation if you contact them. Try this website, where there numbered headstone designs shown. You can email them directly for a price, so you have an better idea of what to expect. http://finditinjamaica.com/creativeheadstones.htm
Good luck!