Hi...have you tried breaking in your Moeck before playing long-term or the higher register, or tried de-clogging your windway? I just ask these first because some people don't, and I found that the proper care insures I get longer play on my instruments (also, I don't know how long you've been playing, so I can't make assumptions). With the plastic one, you can get away with quite a bit in terms of playing, but, ultimately, it will have that "plastic" sound. I had purchased a Moeck Rottenburgh bent-neck maple tenor a few months back (I liked the sound better than the other choice, a Flauto Rondo) and I had to break it in a little at a time to get up to a full hour of play. I will admit that the lowest C sounds a bit muffled, less full than the D. I'm not sure what you mean by "creaky", but I've had good luck up to the high G on my instrument; any higher is tricky to get a clean sound, but I'm mostly a soprano and alto player. I've had to stop recently because I had surgery (still recovering), so going back to it, I'll have to start the break in process all over again.
I had to pay around $750 or so for my tenor, new. Truly high-end tenors will hit the thousands, and bent-neck tenors are harder to find, and what I need. I play the range from sopranino up to tenor, and I have plastic backups for all of them, though I will need to get a bent-neck plastic tenor since I can't play the straight one without lots of discomfort.
http://www.moeck.com/en/recorders/pract ... order.htmlhttp://www.lazarsearlymusic.com/Recorde ... r_care.htm (check his page out for a list of different recorders, even if he may not have them in stock)
http://www.dolmetsch.com/completerecordercareguide.pdfI've not done enough research on tenors, unfortunately, since I knew I could not get more than a mid-range instrument, but here's a site with links various recorder makers:
http://www.recorderhomepage.net/instrum ... ry-makers/