Oh absolutely, which is why I wanted something similar. I'm aware I won't get a cheap rubber that performs the same.
I just want a similar level of hardness and speed for the sake of not needing to re-adjust too much on my shots.
I just want to practice attacking half-long balls without risking my nice setup. It's to get past that mental block where I'm afraid of attacking them or half-ass my shots/butcher my technique.
The bad news is that it is largely a waste of time to look for something that plays like Spring Sponge.
The good news is that a lot of rubbers play well with the new plastic ball. ESN has produced a lot of new generation stuff to play with the plastic ball and many of its historical offerings do a good job as well.
From the ESN first Tenergy-like generation, I like Fastarc G-1 and C-1, but Genius, Hexer, Baracuda, Xplode, Eakza 7 and Vega Pro all have fans. And they are fairly cheap usually, they won't get you Dignics 05 effect, but you can use good technique with most of them and get very good results at levels below the top.
The next generation of ESN rubbers I am a bit less familiar with but I liked those as well. I mostly played Evolution MX-S because I don't like stuff that is boosted and loses its speed after a few months - I prefer stable performance rather than great performance followed by a big drop off. So I didn't really like the Rasants and Bluefires and even Evolution MX-P.
Most top level rubbers from ESN today, the Rasanters and the Dynarz and K3s, the issue is really whether you are ready to change after a period because of the way the booster wears off. But they all respond well to advanced technique. None of them are so much cheaper than Dignics that they fit your criteria. If you can't spend something in the realm of $40 or £40 on a rubber or more realistically $55 or £55, you have to manage the performance of the rubber yourself. Most of the newest ones are more targeted at being like Dignics 09c. But there are usually Dignics 05 analogs as well. But none are extremely cheap. And while one will have to adjust if changing equipment, it isn't a crazy or special adjustment, just lots of training hours to get used to the equipment.
I use a hard sponge, soft topsheet rubber right now from 2018 I believe called Golden Tango from Joola. It is a slower Dignics 09c to me, and I think Joola has a more boosted hybrid version (which if you have understood my rantings so far, I have no interest in). The main reason I use the rubber is that I know a USATT 2400 player who uses it on his forehand and I have a lot of experience using harder and tacky rubbers on my backhand (you need bigger swings but there are tradeoffs in pushing and control). It costs me about $36-$40 per sheet. I use it on reasonably fast carbon blades.
My main point in all this is that if you can't spend £45 on Glayzer, just get something that a player you like plays with and get used to it. I think we have USATT 2400+ using Fastarc C1 If Sarah Jalli's profile is correct, I make this point to say that once you know a player at a respectable level is using equipment to play the way you want to play, then you can tell the equipment will not be the main barrier to your development. I used Fastarc C1 until very recently with no regrets. One could definitely use G1 as well.
Of course ignore all this if you are at a really strong level already. But for me, while money is not a problem for me per se, I just prefer something I know a good player uses and whose performance doesnt change a lot throughout the life cycle of the rubber.
Finally Dignics 05 lasts a long time. If you buy and use a sheet, you could use it for up to a year. Maybe even more. You just have to put the racket in a case, clean it with distilled water and avoid leaving it out in hot weather. There is a good case to be made that most amateurs who want to use Dignics would get more value actually using it than testing tubbers that don't play like it. But the upfront cost affects their decision making adversely.
