I've fixed up pedals that looked as rusty as that one. A bit of work, but most of them are pretty functional and look way better than what I started with.
As to selling it as is - I wouldn't expect to get much for it.
About the pedal you're looking to buy - it wouldn't be my first choice. If you want an inexpensive pedal that plays and holds up well, look for an entry level Yamaha pedal, like this:
That's the current one, but there are similar older, discontinued ones that you can pick up for pretty cheap.