The cost of expenses that we made in our day to day life also changes with the need and desire of the head of expenditure. Sometime the cost of same item changes with the need of the person. The cost of Same vehicle changes with the period or cycle of the business he is doing.
Same thing happens in the Financial Planning also. If you have sufficient Cash Surplus in a particular time then material of Rs.1 lacs also doesnt matter, but if some one is running through financial crunch the cost of Rs.10000 is also higher.
At the time of need, spending lac rupees also doesnt matter and if not required spending Rs.10000 is also wastage of money.
If Someone have a good opportunity to earn handsome money, cost of 20% per annum is also not high, but if the margins are thin, then cost of 10% per annum is also very high.