There should be a way to flag memos.
The price should not be increased, because even honest services use memos.
Spam is one problem, the other is scam. Most of the resteem services are totally overpriced or/and didn't do what they promise.
To avoid being flagged, they only communicate by memo.
The newest spammer we've noticed is this:
https://steemit.com/@haji
The account is already older, but it is probably new in the spam business.
He hasn't learned yet better not to leave any comments.
Also he scams because he promises upvotes to 20 SBD/STEEM.
This is a typical example.
@resteem.bot
https://steemit.com/@good-ali/transfers
18 days ago Transfer 5.229 SBD to haji
They always invest money to spam, most time from exchanges.
We think this a noob spammer.
@resteem.bot