Hi buckeye_614,
Your budget may be too low for a latex mattress or even a latex/polyfoam hybrid that uses thick enough layers of latex for your body type and you may need to consider a mattress with other materials that are also very durable. High density polyfoam (in the 2 lb range and above) or memory foam with 5 lb or higher density with either a strong innerspring or a good quality polyfoam support core may be a suitable option that is in a lower budget range
Alternatively you may want to consider a mattress that uses synthetic Dunlop latex or mostly synthetic latex (if there are any available in the area) although I would tend to lean towards a higher natural latex content in Dunlop latex with your higher body weight.
If you don’t find any suitable mattresses in your budget range locally then some of the members of the site listed in post #21 here that sell latex mattresses online have some lower budget options available and may be worth talking to if you are comfortable with an online purchase.
There are also some online memory foam options listed in post #12 here that may also be worth talking to.
Phoenix