We went last year on holiday two adults and an 8 yr old , we loved it . Its very humid ( well it was in October ).
we stayed on Orchard road at the Holiday inn , we found it very clean and lots to do , we also ran out of time 5 days wasn't enough ( we did a stop over from the UK ) .
The food we loved , there was enough choice to choose from ... the shopping was amazing and blew my brain , after living in WA for 6 years you tend to forget what's out there
Personally we found the prices about the same as here in WA and a bit more shop around for food and / gifts , food courts were cheaper to eat at but its mainly Singaporean food , which we loved my daughter wasn't so keen .
Sentosa island was fun and I would love to split it another time and stay on both .. advice would be add trip adviser and read through there too