I am looking for a php developer ready to pay upto 1000 or so $
thx. I'll leave it. It won't be easy getting an experienced developer with bitcoin / API knowledge for $1000 but good luck anyway.
Then how much is reasonable ?
You need to spec out the job. Professional developers work on a properly specced job, so they can calculate how much work they need to do.
$1000 isn't going to get you much more than a "template website" with a few graphics thrown it.
If someone turns up saying they can do it for $1000, don't expect the job to be completed, sorry.
When I need a site done, I do a full design document, with wireframe design for every page, plus details of every API that needs to be understood and used.
$5K to $10K is more like it for a reasonably involved cryptocurrency website. And no, I'm not trying to pump the price. I'm not applying. Just saying what you should expect to pay.