Do you have a Total Wine or BevMo near you? Those are probably your best bet price-wise. Although if you have a liquor store with good selection and a good staff, you might consider paying for their expertise the first time around. Your call, of course.
As to what to get - my first recommendation would be to find Pyrat XO. But this comes with a warning - it’s very sweet and has a TON of citrus flavor in it, so it’s not suitable for everyone.
For a more “classic” aged rum flavor, see if you can find some Doorleys XO. Good enough to sip, but cheap enough to mix. Wouldn’t consider it particularly dry or sweet.
Hmmm… If you can talk yourself into spending a bit more, see if you can find the Zaya 12 year old (BevMo has it for 27.00 here). But if you mix with it, I don’t want to know.
Another one that I think is pretty good is the R. L. Seale 10 year old. Haven’t had it in a while, though, so I don’t remember if it runs sweeter or not.
As for the spiced rums, someone mentioned Kraken - I agree. Dark and intense. Kilo Kai is another good one - though considerably more delicate than Kraken.
Another one I’ve tried and liked is the Cruzan 9 - not because it’s extra high quality, but because it has… well, instead of “notes” of vanilla, it has a serious vanilla punch, which I happen to like. If you like seriously vanilla, you might like that too (and it’s pretty darn cheap if you can find it).
One last word of advice - pay attention not just to the brand, but the variety - there can be a big difference between the “entry level” stuff and the higher end stuff produced by the same distiller.
And for anyone that wants to spend a little bit more, try the Ron Zacapa 23Yr Centenario . Many consider it the high end “standard”. My personal favorite.