@waynes world I'd generally say that the EMX500 is not quite as good at bass as Vido, but offers better mids to trade off, letting it be a little more balanced and a lot more versatile. I think it's the superior earbud sonically, but not by a big margin. It is by no means a slouch in the bass department, something that's very important to me. Sonically, my focus is bass with vocals ahead enough to not be ruined by the bass. For those two, it really more comes down to your preferences. Another alternative at the real budget range would be the TP16, but you're trading off a little bass again for vocals. If you lived in Indonesia, I'd suggest looking up Initiate Audio as their budget earbud offers wonderful bass and some respectable vocals too which makes me happy, but for me, the shipping fees were more than the earbud's cost, plus another 12 in Western Union fees, which together pushed it to around $45 or so, which IMO is outside budget range at that point.
Considering the two you really like, you're probably not going to find a real upgrade until you get to something like the new Hi-Z 150S which has some excellent bass with a little mids recession, as well as the SeaHF 320 Smart 1.0 which I'm unsure if it's still something you can find. I'm not going to say the 150S is amazing and the best thing ever, but from a bassy perspective, it's very solid for an earbud once EQ hits it.
My progression for that type of sound would most likely be Vido to 150S or Smart 1.0 to Edimun V3 Rhodium or Svara L to Zen 1, all of this assuming they're available. Between Edimun and Svara, the Edimun would be closer to the EMX500 sound where the Svara L is more about bass.
Really though, I would imagine you'll most likely be happy with the EMX500, and if you're not, I can buy your pair so you're not out any money, and I'll have another spare if they disappear on us.