Any card graded by a relatively unknown company is going to have trouble competing wth a copy in similar condition that's slabbed by one of the big names (PSA, BGS, SGC) when it comes to the price it can command. The same is certainly true for HGA cards right now. If we check out recent sales on eBay for some examples, for instance, we find that 1982 Topps Cal Ripken rookie cards in HGA 8.5 (affiliate link) are selling for $20-35 as of September 2022. Meanwhile, copies slabbed by PSA in the same condition (8.5) fall in the $50-60 range (affiliate link). HGA-graded cards have some ground to make up when it comes to selling prices on the open market, in other words. But there does seem to be a market for the HGA cards, at least.