This question has been asked a ton recently. The general suggestions are:
Kershaw Leek (or Blur for ~$80. Blems can be had for 40-50 from kershaw guy)
Buck Vantage pro (great steel, great price, people love it or hate it)
spyderco persistance (can be had for 30 bucks from a certain huge online retailer that sounds like I "am a Zion"
These are pretty much all flat ground. Why do you want a hollow ground? The edge isn't nearly as durable as a convexed and it doesn't slice as nice as a full flat ground.
Why do you need a backup? Would you consider saving up a bit, so you have $80 or so? If you can spend ~$80 you could get a Manix2, which is a fantastic EDC.
Honestly your best bet is to go to somewhere that sells knives online and look at brands you like, sorted by price. Don't be shy about clicking the "next page" button on the bottom of General Knife Discussion". You will literally find 10's of threads in the last month or so asking your exact question. You'll see lots of great suggestions and pictures of knives.
Have fun, good luck.
EDIT:
As an aside, if you want something just like a tenacious...why not get another tenacious? You can get them in different colours. I think there is a red one. You could move 1 red scale to the other tenacious and have a cool looking black and red frankenstein tenacious.