Before I bought a mold, I'd think about buying a box (or maybe just 50 ) each of .495 and .498 balls and try each, including which patch/lube worked best (i.e. tightest group). Might even try 490 and 500 balls, too. Then I'd buy a mold for the best ball diameter.
I have a wall full of Lee RB molds, calibers 36 to 527 RB. They've given me good service over 25 years (although the very last mold, a .440 double cavity is finicky on closing and mating the two block halves together properly). Cost for a single cavity mold is $20 or so, including the handles. Lee molds typically produce an almost invisible sprue mark that isn't always easy to even see.
After Lee, my next choice would be Lyman - steel blocks versus Aluminum for Lee, cost around $50 for the blocks and another $35 or so for the handles, I think. There are other mold makers, e.g. Rapine, that are probably 'better' than Lee, but also priced significantly higher.
SCL