Suspension job - accent viva

guys , need an urgent suggestion /advise. I recently had lot of sound emanating from the rear of my car ( accent VIVA ) . And also sometimes the starter is bit abnormal. It cranks up after two tries. I read a lot on this and came with various solutions in the forum itself. Also I had a petrol leakage. I guessed it because i used to get smell of petrol once i tank it up. And also the mileage has gone awry. Considering all this i went to H.A.S.S to nullify all the problems. So today I got the first call today with a quotation asking me to replace the entire rear suspension. Its as below Shock absorber assembly – 2 sides Linkage assembly– 2 sides Upper spring pad– 2 sides Lower spring bad– 2 sides Balance rod bush– 2 sides Trailing arm -Setting bolt – 2 each RHS & LHS The above work is costing around 13K incl labor :Shockked:. Is this right ? Do we need to cover this as a part of maintenance of any vehicle? Also he said that there is some rubber valve (minimal cost) which sits on top of fuel pump which needs to be replaced. He is of the opinion that it would be the main reason of fuel leakage and also drop in mileage. And when i asked what about the starting problem , he said that first he has to replace that valve and check. It can be a case that the problem is due to this as the required pressure or whatever is not being directed for cranking up. Could you guys help me out with this asap please?

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