A new feature in the next version (1.2) of This Grand Life will be collectibles. I've made a video update demonstrating this feature:
To start a collection, firstly you have to purchase a container from the Shopping Mall. For example to start collecting Stamps, you need a Stamp Collecting Book. I found requiring purchasing a container was the best way to do it, as it allows the player to completely ignore collectibles if they're not interested in it.
Once you have something to store collectibles, you can attend auctions at the Town Hall to start bidding on them.
If you win the auction, the item gets added to your collection. You can only have one of each collectible, even though there may be multiples of the same item up for auction. Each item has a different rarity and prices that reflect their rarity.
In total there are currently about $50k worth of collectible items, ranging from Doll, Coin, Stamp, Video Game and Jewellery Collections. They all contribute towards your possessions life goal, so they provide an alternative to buying Fridges and TVs in working towards that goal.
