My current studio system:

Gigabyte GA-Z68X-UD3-B3
Intel i72600k
16GB DDR-3
Radeon HD 5450

Amazingly that 2600k is still getting the job done. I’m near the edge but would not be considering any PC purchase except for the following problems:

1) My motherboard won’t recognize drives over 2TB.
2) USB is flakey – recognizing a peripheral only happens if the cat stands on one leg and faces east while the dog sings the Oscar Meyer Weiner song.

So I need to upgrade on the cheap! What are my options?

1) Best option: Would be great if I could find a motherboard that would handle my DDR-3 RAM and CPU but am I dreaming? – it’s an old board.

2) Worst option: Buy new motherboard and have to replace the RAM and CPU. Ouch!

3) Or somewhere in between?

I really do need “on the cheap” (medical bills). I would like lots of USB and over-clocking ability if possible. Any advice would be very appreciated. Thanks!

I suspect ultimately the new hardware will be required.  www.newegg.com
Offers reasonable (cheap) combos at times on their daily "shell shocker" deals.  The combos are motherboard/CPU/Memory and sometimes also video (but if you get Intel the built in Intel video will do).
 
You don't need the latest and greatest but if you plan on overclocking (do you really need that?) then you need a "gamer" motherboard (best for that).  Not all CPU's can overclock it takes certain models (e.g. in Intel a "K" model).  Power supply is something not to scrimp on, an old power supply or a cheap new power supply and you are just asking for trouble.  
 
If you want lots of USB that's another "bite the bullet" issue.  However, you have to be careful with that.  Many new/newer model motherboards have only or mostly USB 3.0 ports.  Many older USB 2.0 interface units either do not work or do not work well with USB 3.0.  PCIe USB 2.0 port boards are needed in motherboards with USB 3.0 only.
 

It's going to be hard to find a new socket 1155 motherboard in stock.
A drop-in replacement would most likely be used.
 
A newer motherboard with Intel USB-3 integrated into the chipset will resolve many USB-3 related incompatibilities.
Prior to the Z77 motherboards, literally all USB-3 ports were provided via 3rd-party controllers.
USB-3 had not (yet) been integrated into the chipset.
 
You can get socket 1151 motherboards that support DDR3.
That would allow you to install a 6700k or 7700k CPU (bringing the machine up to current).

Thanks to all for the replies.  @Jim Roseberry... sounds like the best route is keep memory and get new CPU and MB.  Does the 1151 MB hold me back in any way?  Is one just as good as another?   Thanks!
 

Jim Roseberry
It's going to be hard to find a new socket 1155 motherboard in stock.
A drop-in replacement would most likely be used.
 
A newer motherboard with Intel USB-3 integrated into the chipset will resolve many USB-3 related incompatibilities.
Prior to the Z77 motherboards, literally all USB-3 ports were provided via 3rd-party controllers.
USB-3 had not (yet) been integrated into the chipset.
 
You can get socket 1151 motherboards that support DDR3.
That would allow you to install a 6700k or 7700k CPU (bringing the machine up to current).

vintagevibe
Thanks to all for the replies.  @Jim Roseberry... sounds like the best route is keep memory and get new CPU and MB.  Does the 1151 MB hold me back in any way?  Is one just as good as another?   Thanks!

 
In an ideal situation, you'd want a motherboard running DDR4.
That said, current generation iMac and MacBook Pros are still running DDR3... so it's not going to kill performance.
Your choices (actually in stock) are going to be limited.  I'd go with Asus out of what's available.

Hey Jim I really appreciate all the info!