i found one online that sells for around $1,200 new. so the answer to your question depends on several things:
1. WHY does the fuse keep blowing? Does it mean that what's really needed is replacement of a very expensive part? Since you wouldn't be buying machine from an authorized dealer, you'll have NO warranty protection. ALL repair costs will come out of your pocket.
2. Are you willing to buy piles at a time of spare fuses so you can replace them as they blow, just as you would needles?
3. Will this machine keep you otherwise happy for at least a few years?
4. Do you have a fire extinguisher you can keep nearby?
although i admire Janome in general (and own a different model that i LOVE to pieces), this particular model doesn't impress me - especially considering the price of a new one. the sewing area and maximum embroidery field are very small.
i'd accept the machine as a gift, but wouldn't pay for it. your costs along the road could soon amount to more than the cost of a new one.