5k tier miles is now 375 eur, so it should make more sense just to fly it. I had the same situation at the begining and i choose 1 flight waw-ath-lca and ber-ath-kgs as there were good promos. Now there is 30% off on domestic. Good miles you can get for flights to tlv and from waw some dates are bargain, especially if you dont mind late arrivals