and 64GB microsd cards are only ~30 bucks also [2], you can get 128GB microsd cards for under 50$ pretty easy
Putting you at 8GB+128GB for less than a hundred bucks.
Haven't done it myself, but have been thinking about it.
[1]http://www.amazon.com/gp/product/B00VXMY262?ref_=zg_bs_12648...
[2]http://www.amazon.com/s/ref=lp_3015433011_nr_p_n_feature_two...
[3]http://www.amazon.com/s/ref=lp_3015433011_nr_p_n_feature_two...