Cheap source for new springs for my coilovers

Cheapo coilovers on my MK2 Jetta are 392lbs/in and just too stiff for a daily driven 2150 lb car.  The shocks seem fine (no bouncing/pogoing) but I was hoping to replace at least just the front springs with something softer, even a 300lb spring would be a big improvement while still proving good handling.  Also trying to keep this on a challenge budget.  The threaded part of the shock is roughly 2" in diameter and the outer diameter of the spring looked to be about 3 1/4" from a quick measure.  I figured it should be pretty simple to just get a pretty universal size spring and throw it on the hats but I wanted to check first.  The googles told me a 2.5" spring is the standard size for a 2" coilover shock.  For the record, the coilovers are Max Pee Dingrods - Chinesium at their best!

Y'all think something like this would work?

https://www.magnitudeperformance.com/collections/2-5-coil-over-springs/products/5-inch-coil-over-suspension-spring-2-5-id

Any other/better sources?

For challenge budget it's tough to go another route. I will inquire about spring length and potentially going as long as you're able to to assist with preload. On the EGT I went from 7" springs in front to 12" springs and from 5" to 10" in the back and the difference was fantastic with regards to clunks and rattles. Normally I'd say get eibachs, but going challenge budget, it's difficult to resist going with under $30 a spring. 

I believe it was Keith Tanner that reviewed the max peedimg rods and found their springs and perches were an odd diameter and not compatible with regular 2.5 inch springs.

They were 2.75" iirc.

I've bought springs from Suspension Spring Specialist (www.bluecoilspring.com) they have a wide variety and decent pricing. The ones I have used have not sagged yet.

Cheapest parts can be found at the numerous circle track stores on line and around the country.

Springs are measured in the ID, so check that. 

Circle track swap meet is a good suggestion if it's one of their usual sizes. AFCO springs are usually pretty cheap new and I have no complaints about their quality. 

Check out the garage sale section at speedway motors.  I haven't paid more than 50/pair shipped ever.

Thanks for all the tips guys!  2.75" ID sounds right, considering I measured roughly 3.25" OD and the wire is about 1/4" thick.  Next time I pull the wheel off I'll have to take some better measurements of multiple parts so I can see if a 2.5" ID spring might fit.  Hopefully the different car fitments have different specs and it'll work.  If not, I'll have to figure something out.

Also looks like this car is officially turning into a challenge car now, not just a challenge budget, so yay!