I decided to buy myself a present just before Christmas in the form of two S&P/ASX 300 Index (ASX: XKO) shares.

If I have the funds, I like to regularly invest money in my portfolio to help accelerate wealth-building. By consistently putting my money to work, I can hopefully find what I view as the best opportunities at the time.

It has been trickier to find appealing stocks in the last few months following a strong rally in share prices, which has pushed plenty of ASX 300 shares into what I'd describe as overpriced territory.

However, there were two stocks where their valuations had dipped, and I decided to invest.

Tuas Ltd (ASX: TUA)

Tuas is one of the stocks I'm most excited about in my portfolio. This is an ASX telecommunications share that operates in Singapore.

There are three key reasons why I'm bullish about the business.

First, it's delivering impressive revenue growth. The ASX 300 share is winning over Singaporeans with its low-cost mobile offering—in the first quarter of FY25, it revealed a 26.6% year-over-year increase in active mobile services to 1.1 million. This drove a 33% increase in revenue to $35.5 million, showing the business continues to scale rapidly. The company is also gaining traction with a home broadband offering, unlocking another growth avenue.

Second, the company's fast growth is helping it achieve stronger profit margins as costs are spread across more users. The FY25 first quarter saw operating profit (EBITDA) jump 46% year-over-year, with the EBITDA margin climbing from 41% to 45%. I expect the profit margins to continue climbing as the company becomes larger.

Third, I believe the company could eventually grow its customer base beyond Singapore. If Tuas expands to a country like Indonesia or Malaysia, it would significantly extend its growth runway and mean it could make a lot more profit in the future.

I had been buying Tuas shares for the last several months, and I decided to buy more after the stock dropped more than 10% from its peak on 9 December 2024.

Brickworks Ltd (ASX: BKW)

High interest rates have been a painful headwind for building product demand, debt cost, and commercial property valuation. Brickworks is exposed to all of these areas.

This ASX 300 share is one of the largest building product manufacturers. It manufactures bricks, pavers, stone and masonry, roofing, specialised building systems, cement and capital battens. It also owns half an industrial property trust alongside partner Goodman Group (ASX: GMG).

I view building product demand as cyclical, so this period of weakness could be an opportunistic time to invest in the ASX 300 share while sentiment is lower.

Additionally, if the Reserve Bank of Australia (RBA) decides to cut the interest rate in 2025, this could spur demand for building products. A rate cut could also help the industrial property trust by lowering financing (debt) costs and possibly increasing the value of those properties.

I'm excited by the industrial property trust's potential to grow rental profit through organic rental increases and the completion of additional warehouse properties in the next few years, which are currently in the pipeline. When those projects are built, they could also improve the underlying value of the land.

Finally, I also like Brickworks's exposure to the appealing investment business Washington H. Soul Pattinson and Co. Ltd (ASX: SOL). Brickworks owns approximately a quarter of Soul Patts. This investment gives Brickworks a relatively stable and growing capital value and rising dividend compared to its cyclical building product earnings.

I decided to invest in this ASX 300 share after the Brickworks share price fell more than 10% between 30 September 2024 and 20 December 2024.