Where to put 2500 I've got in Zecco?

[Eihli]

I made the minimum deposit to my Zecco account just to get test the waters of investing. I had planned on buying 500 worth of pygmf and putting the rest in vanguard funds. Now I find out pygmf is traded on pink sheets and they'll charge me a commission which I don't feel is worth paying since I'm buying such a small amount and my order for the Vanguard Windsor II fund was rejected because it didn't meet the 10k minimum. I can't find anything about a 10k minimum on Vanguard's site but I'm assuming all of their funds have that minimum.

I'd like to invest this and start putting in another 400-500 a month. What's my best option?