Indeed he is trying to impress you, and spending his money may be a goofy way of telling you how he feels without the need to speak.

He may not know how to word things gracefully, keep in mind that it could be stressful for him as well.

Maybe at some point telling him that you can buy your own things, and that it is not the reason why you're spending time with him, could lead to a more constructive discussion... If you're not afraid to have it, that is