Depends on what you are looking to achieve? The iGo is a nice start, it is actually a slimmed down but otherwise identical version of the eVic Easy Head mod. My first "big battery" was a pass thru which is really nice, especially if you only have the one battery. But are you just looking to have what you need? Sounds like you have a good start. Or are you looking to make it a hobby as well like so many of us mod collectors! If you stay with what you got you are in good shape. You may want to consider a Vision Spinner 1300mAh and the new Mini ProTank or Evod so you can venture into variable voltage at a low cost but with good quality. Then you can work into a Vamo for $40 with variable voltage and variable wattage and a full size ProTank or Smok Pyrex DCT if you like cartos. The ProTanks are similar to the iSmoka Mega and Mini tanks with the bottom coil design, but are made of stainless and glass, the current wave. They will last you a good while and you will save tons of money over smoking and save your lungs too!
Now if you are the Tim the Toolman type you will quickly move into mechanicals and rebuildables, and a kick eventually. That is what I and many here on ECF are into. Mechanical mods are beautiful with great craftsmanship but they come at a price. There are reasonable priced ones that do just fine, but better quality means better contact materials for better conductivity to your rebuildable dripper or genesis style atomizer. The nicer atties aren't cheap either. You will hear names like GP Paps, Poldiac, Nemesis, and GGTS for Greek mods, Nzonic, Bagga, and Titan for Pinoy mods, and Chi You or Astro for Korean mods ... These are top shelf $140 to $300 + for a battery tube, contacts, and a button, but they are worth every penny. Then the rebuildables like Oddysseus, Ithika or Kayfun that have tanks for just under or around $200, or drippers like Nimbus, Trident, and Gryphon in the $75 to $125 range ... again, woth every penny. These are for the collectors or purists. Some are nearly impossible to find like Caravela making them hugely sought after.
Now you can still enjoy this "genre" at much more reasonable costs, they are just mass produced in China and some are really good clones of the more expensive models mentioned above. For $20 to $60 mods you have Sigelei, Kamry, Smok, and Beautiful to name a few, with $10 to $40 rebuildables made by UD, Phoenix, Sailing and Smoktech. Then you have growing in popularity CLONES made by Ehpro, HCigar, and Tobeco that are almost identical to the top shel mods ranging from $18 to $100 ... Some of which score very high in quality and performance, some higher than the original like the EA ... Hehehe.
Lastly you have Hybrids. They are a mix between a mechanical and a genesis style rebuildable. They generally cost a lot and some bigger names are I-Hybrid, Juggernaut, Noble 1, and Zenesis. Now you are in the $200 to $300 range, some out of production going for $2K or more. BTW, tank style or genesis style rebuildables are called RBA and drippers RDA.
Check out vapesquad.com , they have reviews with pricing on a lot of what I just went over. Feel free to PM me any time and I will try to answer any questions you may have. Once you become verified you can start using the classifieds to buy, sell, and trade. That is where i am most of the time ... lol.
Happy vaping!