Which Phono Pre to upgrade to?

I now use a Scoutmaster/ Sumiko Blackbird into the phonostage of a Musical Fidelity A308. If I want to upgrade the phono stage, just how much would I need to spend to get improvement over what I have now.

Is it worth doing at all unless you go to a Sutherland PhD, or a Whest, or a Steelhead?
Check Decware
Gram Sleem Era Gold MKV should be a large improvement.
Decware is an excellent suggestion. I had one in here and compared it to the Whest and Hagerman Trumpet. It held it's own even though I selected the Hagerman in the end. Steve Decker is great to work with too.

I might also suggest you check out the Hagerman Coronet, gets you 80% of the way to the Trumpet. Perhaps the used Cary PH-301 on Audiogon now would be of interest, I owned one and loved it, sold it to finance the Whest, which is a fine phonostage but very system dependent IMO and you'll need to watch for EMI/RF issues. The prices on the Whest are dropping though so there are some deals to be had. Many people also like the EAR 834P which can be had used for about $800 and can be upgraded in the future by Mitch Singerman ifyou want to get more mileage out if it.
I think you should at least audition an Aesthetix Rhea. I listened to one in NYC @ Sound by Singer and was immediately taken by the awesome sound, dynamics, solid bass and liquid midrange coupled w/ crystle clear highs. Dual inputs (XLR & RCA), remote loading and gain, and onboard cartridge demag.
Had same exact rig.

Get yourself a K&K Audio phono stage. This is essentially the kit version of the Art Audio Vinyl Reference phono stage which retails for $4k. At ~$2,000.00, you will be blown away. Go to Kandkaudio.com and poke around.

Check out reviews of the Vinyl Reference while you're at it.
I second the recommendation for the K&K. For about $1900.00 out the door you get a world class phono stage that would be very hard to match at the price.