Welcome to the Pool. I hope we can help you with all of your questions.
First I am going to assume that this is an manual transmission as you state, when you shift.
At 70,000 miles it sounds to as if it is the clutch. It could be the throw out forks or bearing. I could even be the clutch shoes and plate. This all can and should be check and repaired at the same time as it is all bundled together.
If it is the transmission and it is a manual, they are easier and cheaper to repair then an automatic tranny.
If you mean it is just the lever is getting harder to move, then the linkage just may need to be lubed.
Here is an interesting site I found. Just give it a click.
S-10Hope this helps you and gets you an the right track. Don’t wait to long as when it fails, you won’t be able to get it in gear at all.