I think any of the suggestions posted would be good.
The box mod is great cheap way to try VV vaping, but the only downside is their not as sturdy as alot of the tube mods since their plastic.
The BuzzPro and IPro are both much cheaper than the Provari/Darwin and people seem to really like them. They both have a dial to change the voltage like a box mod does. IPro is longer but skinnier, while the BuzzPro is shorter but fatter. The buzzPro has some new colors you can get it in that look really nice. The Ipro is $30 cheaper though.
The lavatube is a very affordable VV device. You can get the whole kit for only $99 and with the coupon code it's about $90. Or if you already have the batteries and charger you can buy just the PV for $69, and I think it's about $63 with the coupon. I haven't used the lavatube yet but people seem to really like it. A definite plus is that it has an LCD screen like the Provari and you can change the voltage in .1V increments, which some people like more than a dial to change voltage bc you know the exact voltage your vaping at. You can get the lavatube in silver now too instead of only black and I'm pretty sure they are going to offer it in red as well, but right now it's just black or silver.
In the end I think you'd be really happy with any of them. If I had to pick though I'd prob go with the lavatube just because of the price. It's almost half the price of the BuzzPro and it's got an LCD screen like the Provari which will allow you to change the voltage in .1increments and find your perfect vape. Even if it doesn't last as long as the BuzzPro, you could basically buy a second one and still spend about the price it costs for 1 BuzzPro. Also it's not a ton more than the VV box mod, but will be alot sturdier and should be able to take more of a beating. I'm right out of college and pay for school myself so I def know what it's like to be on a budget. Right now I'm completely satisfied with my Epower, but if I do ever end up buying a VV PV, I'll prob end up getting a lavatube just bc it's a nice VV that won't break the bank.
But like I said, I think you'll really like any of them.
Goodluck!!