If you decide to buy a scanner make sure it has a dust removal feature otherwise you will not have enough time in this life to do the post processing clean up of the resulting scans. It is enormously time consuming and may not really be all that succesful
If the slides are very important to you consider having the ones that really matter done commercialy, it is not cheap but will probably work out better in the end.
A good scanner is not that cheap and once you have used it it will probably gather dust unless you sell it.
I bought an entry level model and that was a mistake.
Sorry to sound a bit negative (sorry about that :-) ) but I think you will find it a time consuming project.
I thought I would digitize my slides but I ended up actually doing just a small percentage after I got going, the dust and dirt on the slides is a major factor.