Vet bills for a friendly stray cat

This stray kitty has been following me around every time I go outside looking for attention. Just today he followed me halfway to a cafe before I decided to head home and drive there to keep him from getting too close to a busy road.

I'd love to take him in, but I already have cats and really can't until I take him to the vet and get his shots, get him dewormed, and checked for FIV and FeLV. I really don't know how much it's going to costs, but I know I can't afford this suprise expense right now on my grad stipend. If anyone would be willing to help me out, I would really apreciate it and I'm sure he (or she?) would too!

Thanks so much!
Corinne