It's cost effective if you do the job yourself and you know what shaft suits you. Where are you based, Dave? What's your 5 iron distance? What shafts are in them already?

Once you decide on the shaft - and if you decide on a shaft in a demo set, you need to get a demo club made up of the shaft/head combo you intend to play to be certain that it is still the one you want, if you supply the shafts/grips then somewhere in the region of £8-10 per steel shaft which would include swingweighting, loft/lie adjustments, spine/FLO, any extra ferrules, any special tipping/shaft instructions, and any grip build-up. The MX-25 is a .355 taper shaft if you are going to start looking at shafts yourself.

I am based in Reading. The irons are new so I am not looking to change them for probably 2 years. 5 iron goes about 180 (sometimes)... I have dynamic gold sl at the moment..

Interesting, I have the MX25's and although I love them I feel the standard shafts are a little bit of a let down so have been thinking of upgrading them. I have a naturally high ball flight and I lose alot of distance with anything 6 and longer as I blieve I hit the ball to high...

A potentially simple/cheaper solution than a shaft change is to try a lower spinning ball, and/or altering your angle of attack. Of course it may be the shafts. If you have the DG SL, they don't suit everyone. Your tempo, swingspeed, transition, physique, flexibility, strength, co-ordination are all factors to take into account when choosing a new shaft. And demoing as many as possible is very important.

True, but i really don't want to start changing what i class as a pretty solid technique / swing just to cure the loss of 10 yards or whatever on a long iron. I prefer a steeper angle on my short irons for control and don't want to ruin my whole game!

You said "....and I lose alot of distance with anything 6 and longer as I blieve I hit the ball to high..." I took that to mean far in excess of "...loss of 10 yards or whatever...". You might want to get the lofts checked on the MX25's as they are a soft metal, and if you are a range rat then they might have been affected by the hard mats and account for some of the difference in distances. Good luck.

I think that I am a long way off actually changing the shafts. I have a long way to go with my technique yet. Once I get down to single figures and my technique is sound then I can start trying different shafts etc..

Stuart, there may be several things at play here. I have had the opposite problem, to0 much spin with 7,8,9, the ball drops at the apex. The 6,5,4 and 3 are fine, the ball carries. The culprit was the DGs, I had a very stiff shafts heavy shafts and as most players I am sensitive to feel, the stiffness allowed me to hit hard. I went to XX stiff and hit even harder, so the spin just kept going up. So I have had to changed to a lighter shaft with a stiffer tip (PX6) in an effort to sort it out. 7 iron was 150 5 iron 190. You seem to have the opposite problem, but as RGJUSA has said, you need to work through it, probably with some help to narrow it down. I have taught myself how to shaft my irons to keep the cost down, its not easy unless you understand certain principles. Better ask a really good fitter who understands about transition, release and tempo, and how these interact with the shaft. If they just use swingspeed and say 'stiff', run a mile. I don't have huge swingspeed, 110 with a driver, but have had to leave XX shafts, Tiger uses X100s tipped, I have given up on XXX100s, soft stepped once. Take some time and you can reap the rewards.