Minimum budget for triund trek to and fro from Delhi is approximately 4k which includes travel, stay, food!
Day1- Night travel from delhi to Mcloedganj
Day2-Trek uphill,carry enough water & food. Tent also can be rented from base and is available uphill too. Night stay at triund top in a tent.
Day3-Trek down, visit tea gardens if you wish and take a night bus back to Delhi. This way you can save on accommodation cost and time too!
If you thinking just for triund trek or dharamshala and mcleodganj inclueds if just want to stay one night then max 1000-1200 for triund and if you count for all then max 5k for a 3-4days including travel from delhi/chandigarh.