[villagetinker]

I would not bother with cassette tapes, unless these are unique or one of a kind recordings. Audio transfers (records, cassette tapes, open reel tapes, etc., tends to be a time consuming task. Start, stop, and file naming generally need to be completed for each song on each tape. There are 1 or 2 firms in the area that advertise in the Daily Sun and do this type of work. As I have not used them, I have no idea of the quality or cost of these services. You might take a look into the digital music sites to see if the cost of purchasing the songs you like would be less than the cost of transferring much lower quality tapes, just my humble opinion.
If you are a DIY type, there are analog to USB converters that will allow you to plug in a cassette player to your computer, digitize the analog and save the file on the computer. later you can determine how you want to transfer the files to separate storage media. 8mm films are much trickier, and while I have seen some DIY solutions, I have not tried any of these. Most of the ones I have seen involve the projection of the film onto a suitable screen, and a digital camera (with or without sound) to produce a digital video recording.
In any case, I hope you can find a cost effective solution.
By the way I am getting rid of lots of cassettes and a dual cassette player (I think it still works), let me know if you are interested.