Looks like all scammers here. A job like this should cost you much more than those prices.
Yep, you get what you pay for typically and just because someone offers it for a lower price than another it doesn't mean the quality will be worth the discount. There are some factors to consider in a task like this that will make you either celebrate the day you met your developer or curse it. We can do it - escrow with someone known on the forum and trusted is our preference anyhow and we're easy to work with. Our quote for this is $1500 in XMR.