Slides to print.

Depending on the number of slides, just buy yourself a decent flatbed scanner, like an Epson V500/v500/v700 etc and scan them yourself.

Slides can be quite tricky to scan well. If they are under or overexposed too much most scanners will struggle to get the exposure right and may give a colour cast. The best way to scan them is with a drum scanner (these are expensive and hard to come by and I'm sure most places offering to scan slides won't use a drum scanner).

I personally use an older Epson V500 I got about 9 years ago for around AU$350. At the time, the cost of developing and scanning a roll of film in the lab was about $21. Developing alone was about $5 so once I scanned about 30 rolls of film myself, at a higher resolution with better control than the lab I was using, I had broken even.

Another option that may be cheaper is to use an ipad/tablet with a light table app and place the slide onto the tablet to backlight it, then use a phone with a macro lens/setting or a DSLR to reshoot it.

You can also buy slide duplicator. A tube that goes onto a camera, put the slide in the end, hold it up to the light and take a picture. That, I think, could be your easiest and cheapest option.

https://photo.stackexchange.com/questions/96037/copying-slides-with-a-50mm-lens-instead-of-a-macro-one