Prices on ebay do drop in the summer. Then again, what is listed is quite often the stuff that the owners could not sell in the season ie: tat.
If you want to improve, take some tuition before spending any money purchasing equipment. Rent some modern skis and boots, and you will be taught up to date methods for skiing. When you do choose to buy modern equipment, you will be able to use it properly, and will have a good idea what you want to buy.
These days, it seems quite common for folks to try black graded runs by the end of a weeks' tuition, on shorter modern skis.That sentence makes me feel really old :shock:
It is quite possible to get old skinny skis to carve well. The folks that managed it, spent plenty of weeks being taught how. I was one of them!