endoscopic sinus surgery is nothing but clearing disease from your sinuses without injuring normal structures using a nasal endoscope and specialized instrumentation. there is no particular surgery alternative to endoscopic sinus surgery which uses laser.
there is only one alternative surgery which is done in selected cases which is known as balloon sinuplasty. which uses small balloons to open your obstructed sinuses which costs more than regular surgery
I do LASER assisted Nasal Endoscopic Surgery under GA. It is a short stay surgery.
I also do Ballon Sinuplasty which is suitable for some cases like Frontal Sinusitis.
All these new age procedures are expensive.
About conventional FESS, you may have been misinformed! In Mumbai the total cost of hospitalisation is about ₹65000...the ₹30000 being only the Surgeon's & Anaesthetist's fees! The same costs about ₹55000 here in Bengaluru.
LASER surgery costs about ₹20,000 more as the LASER charges and consumables add up to the basic cost.
Balloon Sinuplasty kit(disposable) costs ₹40000, so that is in addition to the basic FESS cost. ( but it is worth it only in case of Frontal Sinusitis).
I will need more info about your case like your CT-PNS images to evaluate and help decide which procedures suit you best.