You spend quite a lot recently.
I would say, 'You've spent quite a lot recently,' or 'In recent days, I've noticed you're spending quite a lot.'
You spend quite a lot these days. or, 'You're spending....
You spend quite a lot nowadays. 'Nowadays' is, I think, a term used more to comment on recent general trends and behaviors. For example, one might hear, 'People nowadays don't sit down to dinner together as much as they once did.'