Rereading your proposed idea and it would make it MORE likely for people to scam.
Lets look at it from the PoV of someone who is willing to sell/buy the services of a decoration for RL cash (or gold).
With the current system, they can say “sub to my patreon and get access to my decorating codes!”. You sub, they’re there. Transaction complete. Arguably against the ToS, but we’re adults here, we know how the system works. If it’s not there, chargeback for fraud. 5 minute job.
If they’re a scammer and you sub and someone falls for their pitch of “sub to me and I’ll decorate your home”. You do so and they say “oh sorry, I’ve got a waitlist. It’ll be x weeks before I have availability”. Time rolls around and the scammer is nowhere to be seen. They say “oh sorry, had a family emergency” and so on. Eventually they string people along long enough that they can get away with scamming people who dont wanna fight over the couple of bucks or whatever.