I was unaware till just now that I could get a gmail account and get it to grab over all my yahoo files-- is this difficult and costly?
Not at all difficult and everything about Gmail is free. How you set it up depends a little on what your intentions are with the yahoo address.
If you want to abandon the address, this is the way to go:
Import Emails From Another ProviderTakes all of 30 seconds to set up, and Gmail will pull all your contacts and mails from Yahoo (the actual download will take a while, especially if you have a lot of emails). It will continue to get the mail going to your Yahoo account for another 30 days, giving you time to update your contacts on your new address. I'd then set yahoo mail to auto-forward to your new gmail address, or to set a vacation message that will give people your new gmail address. The vacation message would confirm to spammers that your e-mail is valid, but Gmail's filter is exceptional - in 5 years, I have not received a single spam mail in my inbox.
If, however, you want to keep your yahoo address, you want to use this:
Mail Fetcher(The yahoo server is pop.mail.yahoo.com)
This option will also get all your Yahoo emails (and you can choose whether or not to keep a copy of the e-mail on yahoo or delete it from there) - and it will do so indefinitely. Moreover, you will be able to send mail using your @yahoo.com address from within gmail. One thing to keep in mind is that the tool checks for new mail once an hour. That may not be sufficiently frequent for a primary mail address.
The second way also doesn't import your contacts. That should be fairly easy to do manually. See
here for Yahoo instructions (make sure you select exporting as a CSV), and
here for how to importing the CSV file into Gmail.