LOL, you have to think 5 or 10 years before everyone else, not when it's already 'the next big thing'. There's probably 100 guys on this board with the same idea. Just like there are dozens of VR porn affiliates springing up every day chasing tinier and tinier shares of a market that will remain as big as 'black MILFs' for at least the next few years.
Sex dolls are fiendishly difficult to convert actually. Even men with money to burn will research carefully which doll they want and that usually means a cookie with at least 30 days tracking which the few doll programs don't offer. They could come down in price still further with new materials and manufacturing but I can't see high end dolls ever selling for less than $1,000. They're probably as cheap now as they can get with TPE and Chinese factories. Meanwhile, sex robots will always be a lot pricier, especially with the forthcoming Realbotix 'Harmony' setting the bar (and priced at $15,000).
Sex doll sales might be growing, but if a leading company is only selling 5 a day, it's still a paltry market. I doubt very much if more than 200 high end dolls are sold a day in Europe/USA. Compare with the figures of 20,000 a day porn membership subscriptions (not including cams, dating etc) that was agreed here recently to be a big underestimate.
BTW, this is why sex dolls are so popular in the UK right now :
Wolf whistling branded hate crime in Nottinghamshire trial | Daily Mail Online
They will probably ban them soon.