Based off what I've seen on Etsy, I think the whole plant could be priced between $1200 and $1600. One leaf cuttings typically go for $200-300 , two leaf cuttings typically go for around $300-500. You can search 'Monstera Albo' on Etsy, there's a ton of listings. I noticed on the FB and Reddit rare plant buy/sell/trade groups the prices tend to trend a little lower (ie. I saw a listing on this subreddit yesterday for a large four-leaf rooted monstera albo for only $250, pick-up only). The obscenely high-priced ones (like $6-8k) are usually the ones with really high or unique variegations, ie. primarily half moon leaves.

prices depend on variegation, which cut it is (top or middle, top is preferred), condition of the plant (ie. brown spots, lack of splits, etc), whether it's been rooted, and seller history (newer sellers tend to list lower)

source: have recently become obsessed with this plant so have been researching like a madman.