Go down and check coupons out. Remember to check price history if it is available. What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Rolling bearing seat material Bearing steel, Height (Rail) 8mm, Length(Rail) “100mm/200mm//300mm//400mm//500mm
600mm//700mm//800mm//900mm//1000mm”, Height (Block) 10mm, Width (Block) 27mm, Length(Block) 46mm, Width(Rail) 12mm, Quantity 1pcs
Banggood
Banggood warehouse is located in China. I couldn’t find any coupon for this product on latest product update.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGc6717d, BGherra, BANGGOODSD, BG83416b, BGGines, BG41677, BG55ef0c, BGHITD21, BG5c6e66, BGMCT01, BGMACHI06, BGTACC18, BG589b2e, BGHTT15, BG20236Tool
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Machifit MGN12 100-1000mm Linear Rail Guide with MGN12H [EU] ($-3)
Price history and price alert
Here is price history (for all/most countries) for Machifit MGN12 100-1000mm Linear Rail Guide with MGN12H.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).
. I don’t think there is an active coupon right now – at least in my database. I don’t really know if this price is reasonable, coz there’s no price history in my DB.