Cointreau almost all sandalwood in perfumery is synthetic now and some of those just make my stomach churn (smells like newborn poo to me).
The exception is Tauer's Miriam. I like all other woods but the creaminess of sandalwood is not my thing.
Another way of making perfumes affordable is splitting bottles. This thread might have enough lovers of Coromandel or Tuscan Leather to make it work. For most people, 10-30 ml of one perfume is more than enough.
Should I list links to niche perfume houses from where you can directly order samples? For me, for a long time now it has been about the journey, not the destination.
Finally, some of the classics have been altered and cheapened almost beyond recognition - that may apply to some of the things you find at discounters. I stiil recommend reading The Snob: Perfume or Luca Turin's guide - you'll get dozens of must-try ideas from them...
For me, the cheapest really good perfumes are some masculines like Yatagan or Antaeus. Yves Rocher do decent quality inexpensive stuff, but none of it is really me. I've given up and buy what I really love - often a sample size is enough but I also use duty frees and sometimes support my favorite perfume stores too. I buy nice clothes and makeup and shoes - why should I scrimp on perfume?
Read perfume blogs - some of them organize bottle sales and swaps. If you get a few 'fume friends, you can swap samples (send someone here everything that makes you go yeugggh - tastes are very individual and you might get something interesting in return).