You can get a new Martin high end mahogany tenor uke for $1000 to $1200.
http://www.elderly.com/brand/180U_MARTIN.html - Figure 10-15% profit included here. The price quoted in the link brian1 posted is not a bargain. It is not a bad price but you can buy that ukulele new for under $1200. I did!
Does this ukulele look to be in good shape? Wear marks are OK but cracks need repaired. Luthier rates are $60/hr where I live.
If you can't play ukulele get somebody to play it for you. A video would probably work if available. In any case if you don't like the sound don't buy it. Your ears should really like the sound of an instrument but that may not be relevant to you at this stage of your career.
Tenors are a popular size uke. They are a little louder than Concert and Sopranos because of the body depth. The big consideration is scale length. There is a 2" difference in scale length between each size. If you have big hands tenor is probably the way to go. If you have tiny hands maybe not. You to the local guitar store and hold the different sizes to get an idea of this.
Martins are considered to be the Rolls Royce of the ukulele world. They hold their value well. The Style 1 and 2 tenors were discontinued in 1965, but have since been reintroduced. There is some rarity value there. The grover tuners might be original or might be replacements.If they have a serial number check with Grover. Martin may be able to give you this info too.
Resale is tricky. I have no experience in selling vintage instruments. The real issue is timing. If you have to sell quickly to raise money odds are you will take a loss. If you can wait you should be able to make at least some money. If you wait 20 to 30 years and don't have to sell quickly you may make more money and should keep up with inflation besides. It is possible you could make a good rate of return on your investment.
Your real rate of return isn't monetary. It is the fun, and joy you get out of it. That will be dependent on how much time you put into it too.
This is what a an older Martin Mahogany Tenor can sound like:
[video]https://video.search.yahoo.com/video/play;_ylt=A0LEVih8oZdUGeIACGoPxQt.;_ylu=X3oDMTBsa3 ZzMnBvBHNlYwNzYwRjb2xvA2JmMQR2dGlkAw--?p=Iz+rainbow&tnr=21&vid=546DD08F7C9D0F7E8317546DD 08F7C9D0F7E8317&l=222&turl=http%3A%2F%2Fts4.mm.bin g.net%2Fth%3Fid%3DUN.608049584336275247%26pid%3D15 .1&rurl=http%3A%2F%2Fwww.dailymotion.com%2Fvideo% 2 Fx2g43w_israel-kamakawiwo-ole-over-the-rain_music&sigr=12h38bvl4&tt=b&tit=Israel+Kamakawi wo%26%2339%3Bole+-+...Over+The+Rainbow&sigt=11fmplf0t&back=https%3A% 2F%2Fsearch.yahoo.com%2Fyhs%2Fsearch%3Fp%3DIz%2Bra inbow%26ei%3DUTF-8%26hsimp%3Dyhs-001%26hspart%3Dmozilla&sigb=12m2ovr2s&hspart=mozil la&hsimp=yhs-001[/video]
Edit: I have re-read these posts. I can't evaluate what the folks are saying about value. There is one thing I am in strong disagreement about. Changing out the tuners for good tuners will not decrease the resale value and will probably increase it a little. One poster indicated friction pegs were OEM. Probably true. Martins are player instruments worn out tuners will not generate increased price amongst players.