The WA is fine. Both it and the Littmann are good. I think there is value in learning on good equipment. Early on, it's good to know that if you aren't hearing something that it isn't just poor equipment but rather just inexperience and poor technique. It's still frustrating, but at least you know to keep trying and that eventually you will get it; with crap scopes, you always wonder if you're limited by the tool itself rather than your ability to use it.
Once you know what you're doing then using an isolation scope or something else cheap is probably fine for most applications.