Need monitor purchasing advice (on a tiny budget)

Hi
So I'm buying some budget monitors for mixing (I have plans for a better pair) but for now I need a budget pair. My options seem to be
Alesis Elevate 5 (used)
Tascam VL-S3
Mackie CR3
M-Audio AV40
Samson MediaOne BT3
Which of these do you think I should go for? If anyone else has other suggestions (or knows of a good used deal on a decent pair), please let me know- I'm open to all options. Thanks!