It's not so complicated, though it depends how much quality you want to put into the code. Proper error handling and passing failed payments back to the queue with some log events and prioritising, it can be quite a job.

If you just want a simple bit of code to just "send" and nothing more than use blockchain "wallet api", not their other one, it is not reliable enough. I think they have a little bit of php example code there on the site also.

Regards

Aris