Latex bed person here. As long as your bed provides a firm, even foundation (no sagging or body impressions to overcome), a latex topper will make a big difference and could give your bed a total makeover. Keep in mind that latex can sleep a little hotter than a traditional mattress and it's hard to pin down the differences between firm/medium/soft for different companies in addition to dunlop vs talalay.
Both my kids have 1" latex toppers on their Ikea twin mattresses. Since I lay on them every night to put them to bed, I actually know how nice they are! We have a more expensive 100% latex mattress but purchased the toppers because the kids wanted their beds to be soft and comfortable like ours. I got them the best mix between quality and price I could find. Here's what they have, but with a bamboo cover that I don't see on the site now. Be sure to get a cover. The latex can rip and crumble and a cover really is worth it.
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sleeponlatex.com]
One more data point, we needed a new mattress for our guest room and wanted a latex/foam mattress and ended up with this in medium:
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www.overstock.com]
It was $550 shipped and my in-laws slept on it for a week and then bought one to use as their primary bed in their vacation home. I haven't actually slept on it but I have laid on it a fair amount and it's pretty nice.
Let me know if you have questions, I have bought a lot of beds and toppers in the past few years.